A lock is pressure applied to a joint to overextend the natural direction of movement of the joint, in order to cause either dislocation of the joint or soft tissue damage within the joint.
Locks can only be applied to joints. Once a lock has been effectively applied, there is no escape.
Locks are a very valuable method of controlling free attacks because they offer the defender a range of options from causing extreme pain and dislocation to subtle controlling techniques that cause very little damage to the attacker’s joints. Getting locks to work correctly requires time to learn how the joint works in order to apply the correct amount of pressure at the correct angle to cause the most pain for the least amount of effort.
Effective locks need to apply the following set of principles in order to control an attacker with a minimum of effort.
1. There must be no possibility of being able to escape from the lock once it has been applied.
2. Locks must be applied to joints and the pressure must be applied at the best possible angle to gain the best effect.
3. The attacker must not have any possibility of striking the defender while in the lock.
4. The possibility of the attacker escaping while getting into the lock must be kept to a minimum by the use of off balancing.
5. A range of follow up techniques, either locks or throws, must be possible if the attacker does manage to resist the initial lock.
Locks provide an effective method of defence and of controlling an attacker with minimum damage to the attacker with a minimum of effort by the defender.
Arm locks are those locks which attack the wrist, elbow and shoulder locks. The preference is to operate on the joints which are weaker and progress, if necessary to those that are stronger. The wrist joint is much weaker than the shoulder joint.
The finger joints are the weakest of all joints but are not considered practical for defences against free attacks. Usually in free attacks the fingers are either curled into a fist or are wrapped around a weapon and are very hard to grasp while on the move. Once the attacker has been grasped, or resists an arm lock, it is then possible to get at the fingers to apply a lock to them.
Wrist locks are those locks which act primarily on the wrist joint. The wrist joint can be twisted or crushed in three directions.
1. The hand can be twisted around an axis running through the middle finger and down the palm
2. The palm of the hand can be crushed onto the inside of the forearm, thus overextending the wrist joint.
3. Twisting the hand, when bent at an angle of 90° to the forearm, around an axis running through the forearm.
Each lock can have a number of variations but the primary method of twisting, or crushing the joint is maintained in all the variations.
Locks on the elbow can be done in two ways.
1. By overextending the elbow joint by forcing down on the joint.
2. By twisting the radius and ulna around each other to dislocate the ulna joint from the elbow. This method is unusual in that most people feel the lock in the wrist joint before the elbow, however, the elbow is the joint which is damaged if the lock is taken to its fullest extent.
Shoulder locks act on the shoulder joint by rotating the shoulder joint out of its socket in order to dislocate the lock. All variations of the shoulder joint rely on this method of dislocating the shoulder joint.
Ude gatame Straight arm lock
Ude garami Arm entanglement
Yoko te kube hishigi Side wrist crush
Ushiro ude garami Rear arm entanglement
Ude gaeshi Arm turning
Te kube hishigi Wrist crush
Kote hineri Forearm turning
Kote mawashi Wrist turning
Leg locks are commonly used in ground-fighting, certainly not against free attacks as a first choice. As with arm locks the object of all leg locks is to attack the joints in order to cause damage to the joint. One of the major problems of leg locks is that the weakest of the leg joints are still far stronger than the arm joints so as with many other techniques you have to have superior technique and balance. Putting locks on the leg is sometimes difficult due to the strength of the leg joints; however they can still be done very effectively.
Methods of applying locks to the leg are similar to those on the arm. The joints can be:
1. Twisted to rotate the joint out of its socket.
2. Crushed back on itself, usually with the attacker placing their own leg or ankle in the joint to provide leverage.
Ankle locks are similar to the wrist twist on the arm. They are used to twist the ankle sideways to damage the joint. The major problem of apply a lock to the ankle is that of keeping the attacker from rolling over and spinning out of the lock.
Pinning the attacker is difficult with an ankle lock and they still have their other leg free to kick with. Unless the attacker is forced onto their stomach and a lock applied which stops the attacker turning over or while the attacker is on their back and unable to turn over and cannot strike out with their free leg ankle locks have a limited use.
When looking at locks on the arm and leg it is usual to equate the knee joint with the elbow however, the method of applying locks to the knee is totally different than the elbow. The knee joint is simply too strong to apply locks by overextending the joint. Locks are usually applied in the same way as a wrist crush by driving the foot up to the back of the thigh. Because the knee normally bends this far it is necessary for the defender to place their leg in the joint in order to lever the knee apart. It is not possible to damage the knee unless the defender places their ankle or leg into the joint, the knee is simply too strong to damage any other way.
Pressure can be applied to the front of the knee to overextend the joint but usually requires the full weight of the defender’s body in order to be effective. This is usually done in order to get the attacker to the ground but is never used to restrain an attacker.
Locks to the hip are rarely used because the joint is so strong. The hip joint needs to rotated out of its socket in the same manner as the shoulder joint and this is difficult to do with the arms. The defender needs to use their legs in order to effect locks on the hip. Locks on the hip can really only be done with the attacker on their back which means that their free leg can be a danger to the defender, thus making locks on the hip not as safe as desirable for putting locks on.
Ashi Kansetsu Waza
Ashi gatame Straight leg lock
Ashi kube gatame Ankle lock
Ashi garami Leg entanglement
Ashi kube garami Ankle entanglement
Ashi juji gatame Leg cross lock
Hiza hishigi Knee crush
Gyaku ashi garami Reverse leg entanglement
Gyaku hiza garami Reverse knee entanglement
Yoko kubi gatame Side ankle lock